Senior Full Stack Engineer

Software Engineering

Sphinx Defense is hiring a Senior Full Stack Engineer in Los Angeles, California. Posted 25 August 2026. Apply directly on Sphinx Defense's own careers site — no account needed.

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ABOUT SPHINX

Sphinx builds software to solve complex national security problems in Space. Founded by engineers and technologists with deep experience across commercial and defense technology, we were frustrated by the outdated and insecure technology America's service members are forced to rely on. We're here to do better.

We’re focused on building modern, scalable products with an emphasis on using open source technologies. Expect talented, motivated, and interesting colleagues who emphasize collaboration, transparency, and individual responsibility.

ABOUT THE ROLE

Sphinx is hiring a Senior Full Stack Engineer to join our team building the next generation of mission planning and command and control software for space communications programs. This team is tasked with creating modern, resilient services and capabilities to support the U.S. Government. As our engineering organization continues to scale rapidly, you’ll also play an important role in helping establish strong technical practices, supporting a growing team, and maintaining quality and consistency as we expand.

As a Senior Full Stack Engineer, you will lead the development of intuitive, high-quality user interfaces and front-end experiences for Sphinx’s space vehicle mission planning platform, while also contributing across the full stack. We’re seeking an experienced engineer with strong front-end development expertise and a solid understanding of backend development, APIs, databases, and service integration. You’ll work as an individual contributor while also proiding technical leadership and mentorship to more junior engineers.

What you will be focusing on:

Applying a strong understanding of modern front-end development to build intuitive, responsive, and maintainable user experiences using technologies such as JavaScript, TypeScript, React, Angular, and/or Vue
Translating design mockups, user feedback, and system requirements into functional, visually appealing, and intuitive user interfaces
Building performant, secure, and well-tested web applications with a focus on scalability, automation, usability, and security
Leading the development of critical features across the full software development lifecycle, with significant influence from user feedback, system requirements, design engineering, and evolving customer needs
Designing, developing, and improving APIs and backend services that effectively support front-end applications and system capabilities
Developing and maintaining backend functionality using technologies such as Python, SQL, RESTful APIs, and containerized architectures
Collaborating closely with QA and other engineering disciplines to define acceptance criteria, meet functional and technical requirements, identify defects, and ensure software quality
Writing and maintaining automated unit, integration, and functional tests to validate functionality and ensure requirements are met
Conducting thorough code reviews to maintain code quality, enforce best practices, and ensure adherence to established standards
Advocating for improvements to product usability, quality, security, and performance that positively impact your team and end users
Supporting junior engineering talent through mentorship and technical guidance

You might be a good fit if you have:

5+ years of progressively responsible web or software development experience using modern development approaches
Strong front-end development experience, with a deep understanding of modern UI development principles, component-based architecture, responsive design, performance, and usability
Extensive experience with JavaScript, TypeScript, HTML, CSS, and modern front-end frameworks such as React, Angular, and/or Vue
Experience translating designs, user needs, and requirements into intuitive, production-quality user experiences
Strong full-stack fundamentals with the ability to work effectively with backend systems, including Python, API development and integration, application architecture, and service-to-service communication
Experience working with relational databases and SQL, including querying and integrating data into web applications
Experience designing, consuming, and integrating APIs between front-end applications and backend services
Understanding of modern containerized and microservices architectures using technologies such as Docker and Kubernetes
Experience collaborating with QA throughout the software development lifecycle, including defining acceptance criteria, troubleshooting defects, validating functionality, and supporting release readiness
Demonstrated experience writing automated tests and developing software against defined user, functional, and technical requirements
A strong understanding of software engineering best practices, including code reviews, version control, automated testing, security, performance, and maintainability
Comfort working with ambiguity, self-directing your work, and providing technical guidance to other engineers
A demonstrated ability to own technical problems end-to-end and make sound engineering tradeoffs
Excellent communication skills and experience working with end users and cross-functional teams to design and build solutions that meet their needs
Experience developing, testing, and deploying software within air-gapped or highly secure government network environments
Have the ability to hold and maintain a U.S. Government TS/SCI clearance

Bonus points if you have the following:

Experience designing and developing intuitive user interfaces featuring real-time, 2D/3D geospatial visualizations
Experience building software for mission-critical, defense, aerospace, or other highly secure environments
Actively hold a U.S. Government Secret Clearance

LOCATION

This role is a hybrid role and can be based out of Colorado Springs, CO, Seal Beach, CA, or Chantilly, VA.

COMPENSATION

This role is between $157,000 - $190,000 base salary.

BENEFITS

Compensation includes competitive salary, meaningful equity ownership, profit sharing, employer 401(k) contribution, and 100% employer covered medical, dental, and vision insurance for you and your dependents.

ELIGIBILITY

Must be a US Citizen and be able to obtain and hold a U.S. Top Secret security clearance and be eligible to obtain and maintain a TS/SCI clearance .

EEO STATEMENT

At Sphinx Defense, we are devoted to building a team that represents a variety of backgrounds, perspectives, and skills. Sphinx Defense is committed to providing equal employment opportunities to all employees and applicants for employment without regard to race, color, religion, sex, sexual orientation, and gender identity.

CLEARANCE ELIGIBILITY - This position requires eligibility to obtain and maintain a U.S. security clearance. For more information about U.S. Security Clearances: click here.

To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.

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